The present invention relates to vent plugs for batteries, and more particularly to batteries having bayonet-type vent wells.
Industrial batteries produced in the United States are generally equipped with molded plastic "bayonet" vent plugs such as that shown in FIG. 1. The plug A is inserted into a vent well B in the cover C and rotated a quarter turn to make a tight seal against a rubber washer. This kind of vent plug is removed to allow water to be added to the cell and then replaced.
As illustrated in FIG. 2, a modified version of this kind of vent plug has a flip-top cover D that allows water to be added without removing the plug A. One drawback of these kinds of plugs is that the opening in the neck E of the vent is reduced (compare the original minimum diameter of the vent well opening D1 between the bayonets with the reduced diameter of the plug opening D2 in FIGS. 1 and 2).
This causes two problems: First, it is now more difficult to see the electrolyte level in the cell due to less light and a narrower angle of view. Second, automatic watering guns used to add water to the cells must have a smaller diameter nozzle to access the cells.
Accordingly, it is an object of the present invention to provide a vent plug that allows the convenience of watering the cell without removing the vent plug but which does not restrict the diameter of the opening in the vent well.
Additional objects, advantages and novel features of the invention will be set forth in part in the description that follows, and in part will become apparent to those of ordinary skill in the art upon review of the following or may be learned by practice of the invention.